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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Surface structure and electronic properties of Pt-Fe/C nanocatalysts and their relation with catalytic activity for oxygen reduction

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Malheiro, A. R. [1] ; Perez, J. [1] ; Villullas, H. M. [1]
Total Authors: 3
[1] Univ Estadual Paulista, Inst Quim, Dept Fisicoquim, BR-14801970 Araraquara, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Journal of Power Sources; v. 195, n. 10, SI, p. 3111-3118, MAY 15 2010.
Web of Science Citations: 38

In this work, physical and catalytic properties of Pt-Fe/C nanocatalysts of nominal compositions Pt;Fe 70:30 and 50:50, prepared by a polyol process using a long-chain diol as reducer (hexadecanediol) and oleic acid and oleylamine as stabilizers, are reported. As-prepared materials have very small particle size (2.2 nm), narrow particle size distribution, and homogeneous dispersion on the carbon support. The average compositions determined by energy dispersive X-ray analysis are Pt(75)Fe(25)/C and Pt(60)Fe(40)/C. Data for samples submitted to heat treatment in hydrogen atmosphere to induce Pt surface segregation are also presented. X-ray diffraction and transmission electronic microscopy are used to examine all as-prepared and heat-treated catalysts. Electronic properties are analyzed based on in situ dispersive X-ray absorption spectroscopy data. Measurements of electrocatalytic activity for oxygen reduction show that all Pt-Fe/C have electrocatalytic activities superior to that of Pt/C. Nanocatalysts with a Pt-rich surface have an enhanced performance for the reduction of oxygen but measurements carried out in methanol containing solutions show that Pt-enriched surfaces have an inferior methanol tolerance. (C) 2009 Elsevier B.V. All rights reserved. (AU)